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Unbranched-chain dicarboxylic acids contain two COOH groups. As a result they can yield two kinds of salts. For example, if oxalic acid, HOOCCOOH, is half-neutralized with sodium hydroxide, NaOH (i.e., the acid and base are in a 1:1 molar ratio), HOOCCOONa, called sodium acid oxalate or monosodium oxalate, is obtained. Because one COOH group is still present in the compound, it has the...